Motor pump unit, in paticular for vehicle power steering

ABSTRACT

A motor/pump unit includes a housing and at least one of: an external tank; an ECU axially disposed at the housing of the motor/pump unit; an ECU radially disposed at the housing of the motor/pump unit; electrical connector plugs of the ECU that are radially disposed; electrical connector plugs to the ECU that are axially disposed; a lead frame of the ECU that is configured in the shape of a dish; a lead frame of the ECU that is externally attached to the housing of the motor/pump unit; and a pressure limitation and check valve that is attached laterally of the pump of the motor/pump unit. The motor/pump unit is also one of firmly attached to the steering gear and integrated in the steering gear.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage of International Application No. PCT/EP2006/003376 filed Apr. 12, 2006, which claimed priority to German Patent Application No. 20 2005 006 414.9 filed Apr. 21, 2005, the disclosures of both are incorporated herein by reference.

BACKGROUND

Various embodiments of a motor/pump unit are described herein. In particular, the embodiments described herein relate to an improved motor/pump unit for a vehicle power steering system.

Known motor/pump units include a drive motor, a pump, and a tank. The pump serves to make hydraulic fluid under pressure available to a power steering system.

BRIEF SUMMARY

The present application describes various embodiments of a particularly compact motor/pump unit. In one embodiment, the motor/pump unit no longer has an internal tank, but that an external tank is used. In another embodiment, the motor/pump unit includes a housing and at least one of: an external tank; an ECU axially disposed at the housing of the motor/pump unit; an ECU radially disposed at the housing of the motor/pump unit; electrical connector plugs of the ECU that are radially disposed; electrical connector plugs to the ECU that are axially disposed; a lead frame of the ECU that is configured in the shape of a dish; a lead frame of the ECU that is externally attached to the housing of the motor/pump unit; and a pressure limitation and check valve that is attached laterally of the pump of the motor/pump unit. The motor/pump unit is also one of firmly attached to the steering gear and integrated in the steering gear.

Some advantages of the various embodiments of the motor/pump unit include the following:

-   -   The electronic control unit (ECU) may axially or radially be         attached to the motor/pump unit, it being possible to arrange         the plugs both radially and axially.     -   The pressure limitation and check valve is disposed laterally of         the pump.     -   The motor/pump unit may directly be attached to the steering         gear, may be integrated in the latter, or may also be disposed         at a distance therefrom, provision being made for an external         tank which is connected via lines to the motor/pump unit.

Other advantages of the motor/pump unit will become apparent to those skilled in the art from the following detailed description, when read in light of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is perspective view of prior art a motor/pump unit.

FIG. 1B is a perspective view of a first embodiment of a motor/pump unit.

FIG. 2A is a cross-sectional perspective view of a portion of the prior art motor/pump unit illustrated in FIG. 1A.

FIG. 2B is a cross-sectional perspective view of a portion of the motor/pump unit illustrated in FIG. 1B.

FIG. 3A is a bottom view in perspective of the prior art motor/pump unit illustrated in FIG. 1A.

FIG. 3B is a top perspective view of the lead frame illustrated in FIG. 1B.

FIG. 3C is a bottom perspective view of the lead frame illustrated in FIG. 1B.

FIG. 3 d is a bottom perspective view of the cap plate.

FIG. 4A is a perspective view of the motor/pump unit illustrated in FIG. 1B.

FIG. 4B is a perspective view of a first alternate embodiment of the motor/pump unit illustrated in FIGS. 1B and 4A.

FIG. 4C is a perspective view of a second alternate embodiment of the motor/pump unit illustrated in FIGS. 1B and 4A.

FIG. 5 a cross-sectional perspective view of a portion of the motor/pump unit illustrated in FIG. 1B.

FIG. 6 is a perspective view of the motor/pump unit illustrated in FIG. 1B in a separate arrangement from the steering gear.

FIG. 7 is a perspective view of the motor/pump unit illustrated in FIG. 1B is directly attached to the housing of the steering gear.

DETAILED DESCRIPTION

In FIG. 1A, a conventional motor/pump unit 50 can be seen as compared to an embodiment of a motor/pump unit 60. It is apparent that the motor/pump unit 60 is configured more compactly in every direction. In the longitudinal direction, i.e. upwards referring to FIGS. 1A and 1B, a saving on space results, because the pressure limitation and check valve 1 provided therein (see FIG. 2A) is disposed laterally of the pump 62 and not in the extension of the pump 52, as in the prior art motor/pump unit 50 illustrated in FIG. 2A.

By means of an improved design of the ECU 64 a considerably smaller space is required. As can be seen by comparing the two motor/pump unit 50 of FIG. 1A and the motor/pump unit 60 of FIG. 1B, the ECU 64 of the motor/pump unit 60 (disposed at the lower end of the pump) has considerably smaller dimensions than the ECU 54 shown in FIG. 1A. For this purpose, the lead frame 2 (see also FIGS. 3B and 3C) is configured in the shape of a dish having an inner parting wall 3, some components being disposed above the parting wall and other components being disposed below the same. In particular, the power module 4 and the printed circuit board 5 are disposed on the upper side of the dish, the printed circuit board 5 being populated on both sides. The lower chamber of the lead frame 2 is closed by a cap plate 6, shown in FIG. 3D. The lead frame 2 is completely placed on the lower section of the housing of the motor/pump unit 60, a metal hood 7 (see FIG. 41B and FIG. 4A) being provided, this metal hood 7 encompassing the lead frame 2 and being crimped into a circumferential groove 66 at the housing such that the lead frame 2 is firmly attached to the housing of the motor/pump unit 60. The metal hood 7 also serves as a shield against electromagnetic interferences.

As is apparent with the aid of FIGS. 4A, 4B, and 4C, the plugs 8 of the ECU 64, 64′, and 64″, respectively, may be disposed in different orientations (axially and radially). It will be understood that the FIGS. 4A, 4B, and 4C each illustrated different exemplary embodiments of the motor/pump unit 60, 60′, and 60″, respectively.

As can be seen in FIG. 5, the pressure limitation and check valve 1 is disposed laterally next to the pump 62 in such a manner that fluidically the valve 1 communicates with the side of the pump 62 facing the motor.

In FIG. 6, the motor/pump unit 60 is shown in a separate arrangement from the steering gear 13. Provided is an external tank 10 which on the one hand communicates via hydraulic lines with the motor/pump unit 60 and on the other hand with the power steering valve 11. In the illustrated embodiment, the motor/pump unit 60 may be mounted at a suitable location in the engine compartment.

In FIG. 7, an embodiment is shown in which the motor/pump unit 60 is directly attached to the housing of the steering gear 13. In this arrangement as well, an external tank 10 is used. As an alternative to the embodiment shown, in which the motor/pump unit 60 is secured to the steering gear 13 by means of fastening clamps 12, the housing of the motor/pump unit 60 may also be integrally embodied with the steering gear 13 according to a further development not represented.

In accordance with the provisions of the patent statutes, the principle and mode of operation of the motor/pump unit have been explained and illustrated in its preferred embodiment. However, it must be understood that motor/pump units described herein may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope. 

1. A motor/pump unit having a housing and comprising at least one of: an external tank; an ECU axially disposed at the housing of the motor/pump unit; an ECU radially disposed at the housing of the motor/pump unit; electrical connector plugs of the ECU that are radially disposed; electrical connector plugs to the ECU that are axially disposed; a lead frame of the ECU that is configured in the shape of a dish; a lead frame of the ECU that is externally attached to the housing of the motor/pump unit; and a pressure limitation and check valve that is attached laterally of the pump of the motor/pump unit; wherein the motor/pump unit is one of firmly attached to the steering gear and integrated in the steering gear. 